66 GENERAL ORNITHOLOGY. 



being satisfactory. It is obvious that birds, or any other objects, may be "classified" in 

 numberless ways — in as many ways as are afforded by all their qualities and relations, — 

 to suit particular purposes, or to satisfy particular bents of mind. Hence have arisen, in 

 the history of the science, very many different schemes of classification ; in fact, nearly every 

 leader of ornithology has proposed his own " system," and enjoyed a more or less respect- 

 able and influential following. Systems have been based upon this or that set of charac- 

 ters, and erected from this or that preconception in the mind of the systematist. Down to 

 quite recent days, modifications of the external parts of birds, particularly of the bill, feet, 

 wings, and tail, were almost exclusively employed for purposes of classification ; and the 

 mental point of view was, that each species of bird was a separate creation, and as much 

 of a fixture in Nature's museum as any specimen in the naturalist's cabinet. Crops of 

 classifications have been sown in the fruitful soil of such blind error, but no lasting har- 

 vest has been reaped. The confusion thus engendered has brought about the inevitable re- 

 action; and the newest fashion is decidedly the opposite extreme — that of counting external 

 features of little consequence in comparison with anatomical characters. Much ingenuity 

 has been wasted in arguing the superiority of each of these characters for the purposes of 

 classification ; as if a natural classification should not be based upon all points of structure ! 

 as if internal and external characters were not reciprocal and mutually exponent! But the 

 genius of modern taxonomy seems to be so certainly right — to be tending so surely, even 

 if slowly, toward the desired consummation, that all differences of opinion, we may hope, 

 will be settled, and defect of knowledge, not perversity of mind, be the only obstacle left 

 in the way of success. The taxonomic goal is not now to find a way in which birds may 

 be most conveniently arranged, described, and catalogued ; but to discover their pedigree, and 

 thus construct their family tree. Such a genealogical table, or phylum (Gr. (f)v\ov, phnlon, 

 tribe, race, stock), is rightly considered the only taxonomy worthy the name, — the only true 

 or natural classification. In attempting this end, we proceed upon the belief that, as ex- 

 plained above, all birds, like all other animals and plants, are related to each other geneti- 

 cally, as offspring are to parents ; and that to discover their genetic relationships is to bring 

 out their true affinities — in other words, to reconstruct the actual taxonomy of Nature. In 

 this view, there can be but one "natural" classification, to the perfecting of which all in- 

 crease in our knowledge of the structure of birds infallibly tends. The classification now 

 used is the result of our best endeavors to accomplish this purpose, and represents what 

 approach we have made to this end. It is based upon principles of Evolution which most 

 naturalists are satisfied have been demonstrated. It is necessarily a 



Morphological Classifleation — that is, one based solely upon consideration of structure 

 or form (/iop(^e, morphe, form) ; and for the following reasons : Every offspring tends to take 

 on precisely the structure or form of its parents, as its natural physical heritage ; and the 

 principle involved, or the law of heredity, would, if nothing interfered, keep the descendants 

 perfectly true to the physical characters of their progenitors; they would "breed true" and be 

 exactly alike. But counter influences are incessantly operative, in consequence of varying 

 conditions of environment ; plasticity of organization of all creatures rendering them more or 

 less susceptible of modification by such means, they become unlike their ancestors in various 

 ways and to different degrees. On a large scale is thus accomplished, by natural selection and 

 other natural agencies, just what man does in a small way in producing and maintaining dif- 

 ferent breeds of domestic animals. Amidst such shifting scenes, degrees of likeness or unlike- 

 ness of physical structure indicate with exactitude nearness or remoteness of organisms in 

 kinship. Morphological characters are therefore the surest guides we can have to the blood- 

 relationships we desire to establish ; and such relationships are the "natural affinities" which 

 classification aims to discover and formulate. As already said, taxonomy consists in tracing 



